GENERALLY, you'll look for fish in deeper pockets where they will be out of the current and the food supply is washed to them. However, we have found shallow flats of around 20' where we usually can pickup fish. These fish have freshwater clams in their bellies, which leads me to believe this is a clam bed. With a good depth finder you should be able to see fish near the bottom. As far as where to start looking, look where you see other anchored boats. It's no secret where fish are consistently hooked. Horsetail falls is one of those areas, so are the powerlines above chinook landing. Other places to look would be the wall,upriver from from rooster rock, the viewpoint down river from rooster rock. Water moves fairly fast in some of these locations, and you're in a big, heavy boat, so make sure you've got enough anchor and chain to keep you from dragging. You may have to run your kicker so you don't drag.